Charity Accounting

I have a local charity organisation that has asked me to prepare its accounts and submit to charities commission and companies house ( Company Type: PRI/LBG/NSC (Private, Limited by guarantee, no share capital, use of 'Limited' exemption)

I have never come across this before and was wondering if someone could explain to me the differences and how I would have to prepare the accounts different to the usual limited company.

Also, is there anything specific required by the charities commission that I need to be aware of?